.box{
    width: 100%;
    height: 300px;
    background: #f00;
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
}
.box1{
    font-size: 0.2rem;
    color: #f00;
    width: 100%;
    height:100vh;
    line-height:0.5rem;
    background: rgba(0,0,0,0.5);
    display: flex;
    align-content: center;
    justify-content: center;
}